Light source device, projector and light intensity distribution uniformization method
A light source device for generating excitation light that is irradiated to a phosphor includes: a plurality of light sources that emits laser light; and a microlens array that includes a plurality of microlenses arranged in two directions orthogonal to each other, that is incident the laser light emitted from the light source, and that irradiates the phosphor with the output light as an excitation light. The light source image of the light source at the irradiated surface of the microlens array is elliptical, and the long axis direction of the light source image intersects with both the two directions. A coordinate system includes: a first axis that is parallel to a principal ray of the laser light incident on the microlens array; and a second axis, in a direction in which the laser light emitted from the microlens array or the fluorescence emitted from the phosphor is reflected.
1. A light source device for generating excitation light that is irradiated to a phosphor, comprising:
a plurality of light sources that emits laser light; and
a microlens array that comprises a plurality of microlenses arranged in two directions orthogonal to each other, wherein the laser light emitted from the light source is incident on the microlens array and exits the microlens array as output light, and that irradiates the phosphor with the output light as an excitation light, wherein:
the light source image of the light source on an irradiated surface of the microlens array is elliptical;
a long axis direction of the light source image intersects with both the two directions; and
in a coordinate system comprising: a first axis that is parallel to a principal ray of the laser light incident on the microlens array; a second axis, in a direction in which the laser light emitted from the microlens array or the fluorescence emitted from the phosphor is reflected, that is an orthogonal direction to the first axis; and a third axis that is orthogonal to the first axis and the second axis, respectively,
the two directions intersect with the direction of the second axis and the direction of the third axis, respectively,
wherein when a width of a short axis direction of the light source image is c, and a length of a microlens of the microlens array parallel to the short axis direction of the light source image is L,
L≤3.0c.
2. A light source device for generating incident light of a microlens array that comprises a plurality of microlenses arranged in two directions orthogonal to each other and that irradiates an image forming device, that performs optical modulation, with the output light, the light source device comprising:
a plurality of light sources that emits laser light, wherein:
the light source image of the light source on an irradiated surface of the microlens array is elliptical;
a long axis direction of the light source image intersects with both the two directions; and
in a coordinate system comprising: a first axis that is parallel to a principal ray of the laser light incident on the microlens array; a second axis, in a direction in which the laser light emitted from the microlens array that is an orthogonal direction to the first axis; and a third axis that is orthogonal to the first axis and the second axis, respectively,
the two directions are parallel to the direction of the second axis or the direction of the third axis, respectively,
wherein when a width of a short axis direction of the light source image is c, and a length of a microlens of the microlens array parallel to the short axis direction of the light source image is L,
L≤3.0c.
3. The light source device according to claim 1 , wherein said microlens array comprises a configuration in which a plurality of the microlenses are arranged in a lattice pattern.
4. The light source device according to claim 1 , wherein a microlens of the microlens array has a rectangular shape, and a long axis direction of the light source image and a direction of diagonal lines of the microlens are intersected.
5. The light source device according to claim 4 , wherein an angle at which the long axis direction of the light source image and the direction of the diagonal lines of the microlens are intersected is 5 degrees or more.
6. The light source device according to claim 1 , wherein an angle at which the long axis direction of the light source image and the direction in which the microlenses are aligned are intersected is 5 degrees or more.
7. The light source device according to claim 1 , wherein a plurality of laser lights is emitted from the light source, and a plurality of the light source images on the irradiated surface of the microlens array are arranged in a lattice pattern.
8. The light source device according to claim 1 , wherein:
a plurality of laser lights is emitted from the light source;
a plurality of light source images on the irradiated surface of the microlens array are arranged in a staggered manner; and
a direction, in which a plurality of the light source images is linearly arranged and a direction in which the microlenses are aligned are intersected, the direction being different from a long axis direction and a short axis direction of the light source images.
9. The light source device according to claim 1 , wherein when a width of the short axis direction of the light source image is c, and the length of the microlens of the microlens array parallel to the short axis direction of the light source image is L,
0.5c≤L≤3.0c.
10. A light source device for generating incident light of a first microlens array that comprises a plurality of microlenses arranged in a first direction and a second direction orthogonal to each other and that irradiates an image forming device, that performs optical modulation, with the output light, the light source device comprising:
a plurality of first light sources that emits laser light and that irradiates the first microlens array with the output light;
a plurality of second light sources that emits laser light; and
a second microlens array that comprises a plurality of microlenses arranged in a third direction and a fourth direction orthogonal to each other, and that is irradiated the laser light emitted from the second light source, and that irradiates a phosphor with the output light, wherein:
the light source image of the first light sources on the irradiated surface of the first microlens array is elliptical;
a long axis direction of the light source image of the first light source intersects with both the first direction and the second direction;
the light source image of the second light source on the irradiated surface of the second microlens array is elliptical;
the long axis direction of the light source image of the second light source intersects with both the third direction and the fourth direction; and
the first direction and the second direction intersect with both the third direction and the fourth direction,
wherein when a width of a short axis direction of the light source image is c, and a length of a microlens of the first microlens array parallel to the short axis direction of the light source image is L,
L≤3.0c.